Date created: | Last Updated:

Category: Project

Description: Geologic evidence across orogenic plateau margins helps to discriminate the relative contributions of orogenic, epeirogenic and/or climatic processes leading to growth and maintenance of orogenic plateaus and plateau margins. Here, we discuss the mode of formation of the southern margin of the Central Anatolian Plateau (SCAP), and evaluate its time of formation, using fieldwork in the onshore and seismic reflection data in the offshore. In the onshore, uplifted Miocene rocks in a dip-slope topography show monocline flexure over >100 km, few-km asymmetric folds verging south, and outcrop-scale syn-sedimentary reverse faults. On the Turkish shelf, vertical faults transect the basal latest Messinian of a ~10 km fold where on-structure syntectonic wedges and synsedimentary unconformities indicate pre-Pliocene uplift and erosion followed by Pliocene and younger deformation. Collectively, Miocene rocks delineate a flexural monocline at plateau margin scale, expressed along our on-offshore sections as a kink-band fold with a steep flank ~20–25 km long. In these reconstructed sections, we estimate a relative vertical displacement of ~3.8 km at rates of ~0.5 mm/y, and horizontal shortening values <1 %. We use this evidence together with our observations of shortening at outcrop, basin, plateau-margin and forearc system scales to infer that the SCAP forms as a monoclinal flexure to accommodate deep-seated thickening and shortening since >5 Ma, and to contextualize the plateau margin as the forearc high of the Cyprus subduction system.